How do I get exact Cp plot for NACA airfoil in Ansys fluent?
 

I have done the simulation with C-type mesh(2.5million elements), steady state, K-w SST. My solution converged (Convergence criterion of 10e-06). But in my Cp vs X plot

I am getting an error of '+1'. I imported Cp co-ordinates into excel and added '+1' in each of the Cp value and Plotted graph again. This plot is matching with the original values.

But why am I getting an error of '+1' in Fluent?

Cp plot on fluent
https://drive.google.com/file/d/123B...usp=drive_open

Cp plot after adding '+1':https://drive.google.com/file/d/16Sr...usp=drive_open
Original Cp plot by NASA: https://drive.google.com/file/d/1VkG...usp=drive_open